Genome-wide prediction of topoisomerase IIB binding by architectural factors and chromatin accessibility
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE141528 | GEO | 2020/12/30
REPOSITORIES: GEO
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Project description:Specialized topoisomerases solve the topological constraints arising when replication forks encounter transcription. We have investigated Top2 contribution in S phase transcription. Specifically in S phase, Top2 binds intergenic regions close to transcribed genes without influencing their transcription. The Top2-bound loci exhibit low nucleosome density and accumulate yH2A when Top2 is defective. These intergenic loci associate with the HMG-protein Hmo1 throughout the cell cycle and are refractory to the histone variant Htz1. In top2 mutants, Hmo1 is deleterious and accumulates at pericentromeric regions in G2/M. Our data indicate that Top2 is dispensable for transcription and that Hmo1 and Top2 bind in the proximity of genes transcribed in S phase suppressing chromosome fragility at the M-G1 transition. We propose that an Hmo1-dependent epigenetic signature together with Top2 mediate a S-phasen architectural pathway controlling replicon dynamics when forks encounter transcriptionto preserve genome integrity. Signal tracks in BED format suitable for visualization on the UCSC genome browser can be found at http://bio.ifom-ieo-campus.it/supplementary/Bermejo_et_al_CELL_2009
2009-09-05 | GSE16258 | GEO
Project description:DNA topoisomerases are essential molecular machines that manage DNA topology in the cell and play important roles in DNA replication and transcription. We find that knocking down the enzyme Topoisomerase IIβ (Top2b) increases the lifespan of S. cerevisiae, C. elegans, and mice. TOP2B reduction also extends the health span of mice and alleviates the characteristics and pathologies of aging in multiple tissues. At the cellular/molecular level, TOP2 reduction attenates the major hallmarks of aging, such as cellular senescence, deregulated nutrient-sensing, epigenetic alterations, and lysosomal biogenesis. We observed that TOP2 reduction significantly alters the epigenetic landscape in various mouse tissues toward those of the young animals, and differentially down-regulates genes with active promoter and high expression. Our observations suggest that TOP2 reduction confers longevity effect across species via a conserved mechanism, and may be used as a novel therapeutic strategy for countering aging.
2024-10-10 | GSE278873 | GEO
Project description:A unique signature of neuronal transcriptomes is the high expression of the longest genes in the genome (e.g. >100 kilobases). These genes encode proteins with essential functions in neuronal physiology, and disruption of long gene expression has been implicated in neurological disorders. DNA topoisomerases resolve topological constraints that arise on DNA and facilitate the expression of long genes in neurons. Conversely, methyl-CpG binding protein 2 (MeCP2), which is disrupted in Rett syndrome, can act as a transcriptional repressor to downregulate the expression of long genes. The molecular mechanisms underlying the regulation of long genes by these factors are not fully understood, however, and whether or not they directly influence each other is not known. Here, we identify a functional interaction between MeCP2 and Topoisomerase II-beta (TOP2b) in neurons. We show that MeCP2 and TOP2b physically interact in vivo and map protein sequences sufficient for their physical interaction in vitro. We profile TOP2b activity genome-wide in neurons and detect enrichment at regulatory regions and gene bodies of long neuronal genes, including long genes regulated by MeCP2. Further, we find that knockdown and overexpression of MeCP2 leads to altered TOP2b activity at MeCP2-regulated genes. Our findings uncover a mechanism by which MeCP2 inhibits the activity of TOP2b at long genes in neurons and suggest that this mechanism is disrupted in neurodevelopment disorders caused by mutation of MeCP2.
2023-11-11 | GSE201658 | GEO
Project description:A unique signature of neuronal transcriptomes is the high expression of the longest genes in the genome (e.g. >100 kilobases). These genes encode proteins with essential functions in neuronal physiology, and disruption of long gene expression has been implicated in neurological disorders. DNA topoisomerases resolve topological constraints that arise on DNA and facilitate the expression of long genes in neurons. Conversely, methyl-CpG binding protein 2 (MeCP2), which is disrupted in Rett syndrome, can act as a transcriptional repressor to downregulate the expression of long genes. The molecular mechanisms underlying the regulation of long genes by these factors are not fully understood, however, and whether or not they directly influence each other is not known. Here, we identify a functional interaction between MeCP2 and Topoisomerase II-beta (TOP2b) in neurons. We show that MeCP2 and TOP2b physically interact in vivo and map protein sequences sufficient for their physical interaction in vitro. We profile TOP2b activity genome-wide in neurons and detect enrichment at regulatory regions and gene bodies of long neuronal genes, including long genes regulated by MeCP2. Further, we find that knockdown and overexpression of MeCP2 leads to altered TOP2b activity at MeCP2-regulated genes. Our findings uncover a mechanism by which MeCP2 inhibits the activity of TOP2b at long genes in neurons and suggest that this mechanism is disrupted in neurodevelopment disorders caused by mutation of MeCP2.
2023-11-11 | GSE246461 | GEO
Project description:A unique signature of neuronal transcriptomes is the high expression of the longest genes in the genome (e.g. >100 kilobases). These genes encode proteins with essential functions in neuronal physiology, and disruption of long gene expression has been implicated in neurological disorders. DNA topoisomerases resolve topological constraints that arise on DNA and facilitate the expression of long genes in neurons. Conversely, methyl-CpG binding protein 2 (MeCP2), which is disrupted in Rett syndrome, can act as a transcriptional repressor to downregulate the expression of long genes. The molecular mechanisms underlying the regulation of long genes by these factors are not fully understood, however, and whether or not they directly influence each other is not known. Here, we identify a functional interaction between MeCP2 and Topoisomerase II-beta (TOP2b) in neurons. We show that MeCP2 and TOP2b physically interact in vivo and map protein sequences sufficient for their physical interaction in vitro. We profile TOP2b activity genome-wide in neurons and detect enrichment at regulatory regions and gene bodies of long neuronal genes, including long genes regulated by MeCP2. Further, we find that knockdown and overexpression of MeCP2 leads to altered TOP2b activity at MeCP2-regulated genes. Our findings uncover a mechanism by which MeCP2 inhibits the activity of TOP2b at long genes in neurons and suggest that this mechanism is disrupted in neurodevelopment disorders caused by mutation of MeCP2.
2023-11-11 | GSE246460 | GEO
Project description:High-intensity transcription and replication supercoil DNA to levels that can impede or halt these processes. As a potent transcription amplifier and replication accelerator, the proto-oncogene MYC must somehow manage these high levels of torsional stress. By comparing gene expression with the recruitment of topoisomerases and MYC to promoters, we surmised a direct association of MYC with Topoisomerases 1 (TOP1) and 2A (TOP2A) that was confirmed in vitro and in vivo. Beyond recruiting topoisomerases, MYC directly stimulates their activities in vitro and in vivo. We identify a MYC-nucleated “topoisome” complex that unites and increases the levels of both both TOP1 and TOP2, as well as their activities at promoters and enhancers. Whether TOP2A or TOP2B is included in the topoisome, is dictated by the presence of c-MYC or MYCN, respectively. Thus, in vivo and in vitro, MYC assembles tools that simplify DNA topology and promote genome function under high output conditions.
2021-12-09 | GSE181449 | GEO
Project description:High-intensity transcription and replication supercoil DNA to levels that can impede or halt these processes. As a potent transcription amplifier and replication accelerator, the proto-oncogene MYC must somehow manage these high levels of torsional stress. By comparing gene expression with the recruitment of topoisomerases and MYC to promoters, we surmised a direct association of MYC with Topoisomerases 1 (TOP1) and 2A (TOP2A) that was confirmed in vitro and in vivo. Beyond recruiting topoisomerases, MYC directly stimulates their activities in vitro and in vivo. We identify a MYC-nucleated “topoisome” complex that unites and increases the levels of both both TOP1 and TOP2, as well as their activities at promoters and enhancers. Whether TOP2A or TOP2B is included in the topoisome, is dictated by the presence of c-MYC or MYCN, respectively. Thus, in vivo and in vitro, MYC assembles tools that simplify DNA topology and promote genome function under high output conditions.
2021-12-09 | GSE181448 | GEO
Project description:High-intensity transcription and replication supercoil DNA to levels that can impede or halt these processes. As a potent transcription amplifier and replication accelerator, the proto-oncogene MYC must somehow manage these high levels of torsional stress. By comparing gene expression with the recruitment of topoisomerases and MYC to promoters, we surmised a direct association of MYC with Topoisomerases 1 (TOP1) and 2A (TOP2A) that was confirmed in vitro and in vivo. Beyond recruiting topoisomerases, MYC directly stimulates their activities in vitro and in vivo. We identify a MYC-nucleated “topoisome” complex that unites and increases the levels of both both TOP1 and TOP2, as well as their activities at promoters and enhancers. Whether TOP2A or TOP2B is included in the topoisome, is dictated by the presence of c-MYC or MYCN, respectively. Thus, in vivo and in vitro, MYC assembles tools that simplify DNA topology and promote genome function under high output conditions.
2021-12-09 | GSE181447 | GEO
Project description:DNA topoisomerases are known to promote transcription in prokaryotes by removing excessive DNA supercoils produced during elongation. However, it is unclear how topoisomerases in eukaryotes are recruited and function in the transcription pathway in the context of nucleosomes. To address this problem we present high-resolution genome wide maps of one of the major eukaryotic topoisomerases, Topoisomerase II (Top2) and nucleosomes in the budding yeast, Saccharomyces cerevisiae. Our data indicate that at promoters Top2 binds primarily to DNA that is nucleosome free. However, while nucleosome loss enables Top2 occupancy the opposite is not the case and the loss of Top2 has little effect on nucleosome density. We also find that Top2 is involved in transcription. Not only is Top2 enriched at highly transcribed genes but Top2 is required redundantly with Top1 for optimal recruitment of RNA polymerase II at their promoters. These findings and the examination of candidate activated genes suggest that nucleosome loss induced by nucleosome remodeling factors during gene activation enable Top2 binding which in turn acts redundantly with Top1 to enhance recruitment of RNA polymerase II.
2011-08-01 | GSE22626 | GEO
Project description:During meiotic prophase, concurrent transcription, recombination, and chromosome synapsis place substantial topological strain on chromosomal DNA, but the role of topoisomerases in this context remains poorly defined. Here, we analyzed the roles topoisomerases I and II (Top1 and Top2) during meiotic prophase in Saccharomyces cerevisiae. We show that both topoisomerases accumulate primarily in promoter-containing intergenic regions of actively transcribing genes, including many meiotic double-strand break (DSB) hotspots. Despite the comparable binding patterns, top1 and top2 mutations have different effects on meiotic recombination. TOP1 disruption delays DSB induction and shortens the window of DSB accumulation by an unknown mechanism. By contrast, temperature-sensitive top2-1 mutants exhibit a marked delay in meiotic chromosome remodeling and elevated DSB signals on synapsed chromosomes. The problems in chromosome remodeling were linked to altered Top2 binding patterns rather than a loss of Top2 catalytic activity and stemmed from a defect in recruiting the chromosome remodeler Pch2/TRIP13 to synapsed chromosomes. No chromosomal defects were observed in the absence of TOP1. Our results imply independent roles for topoisomerases I and II in modulating meiotic chromosome structure and recombination.
2020-03-06 | GSE131994 | GEO